diff --git a/ui/src/views/Baseline.jsx b/ui/src/views/Baseline.jsx
index 23611bd..c145c03 100644
--- a/ui/src/views/Baseline.jsx
+++ b/ui/src/views/Baseline.jsx
@@ -165,6 +165,19 @@ export default function Baseline({ sources = [], sourceId, versions = [], versio
     } catch (err) { flash(err.message, 'error') }
   }
 
+  // Column widths read off the content rather than guessed. ch is the width of a
+  // '0', so for proportional text it runs slightly generous -- which is what is
+  // wanted for an input you are about to type a longer name into. The floors keep
+  // an empty table from collapsing its headers; the ceilings keep one long note
+  // from pushing the numbers off the side.
+  function widthCh(values, min, max) {
+    const longest = values.reduce((n, v) => Math.max(n, String(v || '').length), 0)
+    return `${Math.min(max, Math.max(min, longest + 2))}ch`
+  }
+  const labelW  = widthCh(log.map(e => e.label || e.tag || e.note), 18, 40)
+  const bucketW = widthCh(log.map(e => e.bucket), 16, 28)
+  const noteW   = widthCh(log.map(e => e.note), 24, 60)
+
   function loadLog() {
     fetch(`/api/versions/${versionId}/log`).then(r => r.json()).then(data => {
       setLog(data.filter(e => e.operation === 'baseline' || e.operation === 'reference'))
@@ -341,7 +354,10 @@ export default function Baseline({ sources = [], sourceId, versions = [], versio
 
   return (
     <div className="h-full overflow-y-auto bg-gray-50">
-      <div className="p-4 flex flex-col gap-4 max-w-4xl">
+      {/* Uncapped: the segment table is eleven columns, and at max-w-4xl (896px)
+          something always got smashed no matter how the widths were divided. The
+          blocks that read better narrow keep their own caps. */}
+      <div className="p-4 flex flex-col gap-4">
 
         {msg && (
           <div className={`px-3 py-2 text-xs rounded font-medium ${msg.type === 'error' ? 'bg-red-50 text-red-700' : 'bg-green-50 text-green-700'}`}>
@@ -408,9 +424,9 @@ export default function Baseline({ sources = [], sourceId, versions = [], versio
                   <th className="px-3 py-1.5 font-medium w-6"></th>
                   <th className="px-3 py-1.5 font-medium">#</th>
                   <th className="px-3 py-1.5 font-medium w-20">kind</th>
-                  <th className="px-3 py-1.5 font-medium w-48">label</th>
-                  <th className="px-3 py-1.5 font-medium w-full max-w-0">note</th>
-                  <th className="px-3 py-1.5 font-medium w-36">counts toward</th>
+                  <th className="px-3 py-1.5 font-medium" style={{ width: labelW }}>label</th>
+                  <th className="px-3 py-1.5 font-medium" style={{ width: noteW }}>note</th>
+                  <th className="px-3 py-1.5 font-medium" style={{ width: bucketW }}>counts toward</th>
                   <th className="px-3 py-1.5 font-medium text-right">rows</th>
                   <th className="px-3 py-1.5 font-medium text-right">{log[0]?.value_col || 'value'}</th>
                   <th className="px-3 py-1.5 font-medium">by</th>
@@ -464,16 +480,16 @@ export default function Baseline({ sources = [], sourceId, versions = [], versio
                                        focus:border-blue-400 rounded px-1 py-0.5 text-xs
                                        focus:outline-none bg-transparent" />
                         </td>
-                        {/* One line, clipped. The note is provenance -- it can run
-                            long -- and this row is eleven columns wide, so it used
-                            to wrap and push every row to two or three lines. w-full
-                            plus max-w-0 is what lets a cell in an auto-layout table
-                            absorb the slack and still clip: without the max-w-0 the
-                            column simply grows to fit the text. Expanding the row
-                            shows it in full. */}
-                        <td className="px-3 py-2 w-full max-w-0">
+                        {/* One line, clipped against the measured width above. The
+                            note is provenance and can run long, so left to itself it
+                            wrapped and pushed every row to two or three lines.
+                            Expanding the row shows it in full. The cap is on the div,
+                            not the cell: a max-width on a cell in an auto-layout table
+                            is only a hint, and the column can still collapse to
+                            min-content or grow past it. */}
+                        <td className="px-3 py-2">
                           {entry.note
-                            ? <div className="truncate" title={entry.note}>{entry.note}</div>
+                            ? <div className="truncate" style={{ maxWidth: noteW }} title={entry.note}>{entry.note}</div>
                             : <span className="text-gray-300">—</span>}
                         </td>
                         <td className="px-3 py-2" onClick={e => e.stopPropagation()}>